Integrated circuits include a plurality of different voltage domains, with each voltage domain including components that operate at a corresponding voltage level, with each voltage domain corresponding to a different voltage level. For example, most modules of an integrated circuit are located in a voltage domain connected to a low supply voltage to save power. However, the integrated circuit might also include one or more modules that require a higher voltage level. Accordingly, such high-voltage modules might be located in a high-voltage domain of the integrated circuit. The integrated circuit might also include modules that operate at a lower supply voltage and are therefore included in a voltage domain connected to a relatively low supply voltage. The integrated circuit might include one or more level shifters that change the voltage of a signal used to communicate data between different voltage domains.